reinstall ispconfig

Is it possible to just reinstall one server and what is the procedure to reinstall master in keeping slaves ( dns server, mailserver,dbserver), or just reinstall one slave ( db server for example) in keeping the others servers.

I can reinstall if i'm using glsuterfs?

If I would like to add LVM for var ( to increase space disk more later) with glusterfs. I must add LVM for the directory data ? ( directories where are export-vmail export-vmail-ns export-www export-www-ns ).